Thanks to the wide spread of digital apparatuses exclusively for photography such as video cameras and digital video recorders as well as camera-imbedded mobile terminals and mp3 players, the number of users who create digital data such as videos recently has sharply increased.
Accordingly, the amount of digital data created has drastically increased as well and this has requested the necessity to build a system which can systematically manage and use enormous amount of data.
To perform the management of digital data and make users use such data more easily, various technologies granting tags to digital data through recognition of person have been suggested and a variety of methods which extract the tags from the digital data with higher accuracy have been attempted. Herein, “tag” may be understood as additional data attached to the digital data for rapid access or search to data and it is generally composed of a series of characters or numbers, or a combination of characters and numbers.
One example of technologies required to give a tag to digital data through person recognition is face detection technology. The face detection technology is widely adopted to enhance the image quality of a photo or a video created by means of digital device such as digital camera or video recorder, and it performs a function to adjust a focus point and a degree of exposure with a separate button by automatically recognizing a face or faces if one or multiple persons exist in the photographic range. For example, photography equipment with the face detection function competitively unveiled by Sony, Fujifilm, Nikon, Canon etc. can shot, edit and record photos or videos conveniently by using the above-mentioned function.
Despite the advantages, in case various videos regarding multiple events are randomly created in sequence by a video camera or a video recorder and a user wants to select and replay only a scene(s) on which a specific person appears in at least one of multiple movies or only a scene(s) on which only a specific person appears in one movie, there is, however, a disadvantage that the user must check the location of such scene(s) by fast-forwarding or rewinding function. The more detailed matters regarding the disadvantage are as follows:
First, according to the existing technology, there is a weak point that it is difficult to easily find and replay only the scene on which a specific person among multiple persons who appear in a movie regarding a certain event. For example, let us suppose that a user recorded his or her child's birthday party held during the time from 12:00 pm to 15:00 pm with a photography device and tries to replay it. Many people including family and friends as well as the child may appear on the birthday party video. It is not easy to search only the scenes on which his or her child appears (referred to as “people search”). To search a specific person, the user may need to operate the buttons such as PREV or NEXT of the DVD player or the buttons such as REW or FF of the video recorder, and check the time zone on which the specific person appears (for instance, the user would not know that the child appeared in the specific time zones from 12:00 to 12:20, from 12:45 to 13:05 and from 14:40 to 15:00 until the user pressed the buttons and checked all the scenes). Accordingly, it is very annoying and troublesome to view the scenes on which his or her child appears.
Second, it is difficult to see which persons appear in which time zones in a movie regarding which event on the whole. For example, it is difficult to search information on who appears in the birthday party movie, which persons appear in which time zone or in which time zone the user's child and the child's friends appear at the same time (referred to as “scene search”).